From Beginning to Now
by SupremeMasterOverlordKhurro
Summary: "James is still…" Magnus struggled for the words to best describe it. "He's still stuck in the past, in a way. I believe that he's come back to the modern world too quickly. Physically, he's healthy. But in his mind, he's mixing up the past with the present. He thought you were Will." *Includes Mortal Instruments characters, but focuses on Jem's life with Will before Tessa.
1. Yan Luo

**I don't think I've really ever written a Mortal Instrument fanfiction (besides half finished ideas in note books).**

 **But I've recently made an accounted on that cursed website known as Tumblr. I have no idea what I'm doing, but I made the mistake of looking up James Carstairs. And thus, this story idea came to mind. (By the way, you should follow me! My username is SurpremeMasterOverlordKhurro )**

 **Before I start, here's some background:**

 **This is about a year after City of Heavenly Fire.**

 **By now, everyone knows that Zacariah is actually James Carstairs.**

 **I'm a horrible person and my goal in most of my stories is to make people cry so know that you've been warned.**

 **This first chapter will probably suck, but I promise the next ones will be better. This first one is just kind of an introduction to set the rest into action.**

 **I do not own the series or the characters.**

 _New York, A few blocks away from the Institute_

Jem had been feeling as though he was missing something for a while now. Something other than Will. He was bored being a normal mortal. He wanted to be a shadowhunter again, to once again serve the Angel . He had thought that after losing Will, he wouldn't want to be an active shadowhunter ever again. Jem missed Will more than anything, missed it so much it hurt to even think about him. He didn't think would ever get used to being a shadowhunter without his best friend beside. And yet, after spending about a year watching over Emma Carstairs, he found he once again longed to feel a blade in his hand and experience the thrill of a demon hunt. He figured he would give a try, to see if maybe there was a chance he could become an active shadowhunter once more. But he never told Tess. So when Tessa had been called away for some job the Iron Sisters needed help with, and had dropped Jem off in the New York Institute at his request (claiming he wished to spend a little more time watching Herondales and Lightwoods), he decided to join them on a hunt.

"You're going hunting with a stick?" Jace rose an eyebrow when he spotted Jem's old dragon-headed cane. It had been saved over the generations, and still worked like it always had.

"It's a staff." Jem corrected automatically, remembering a similar conversation with another Herondale. "A very old one at that."

"And old stick isn't going to help you much." Alec came up beside Jace, looking curiously at the dragon carving.

Jem lifted the staff and pressed a button, and the knife sprang out, shining in the pale light that lit the hallway. "An older violin sounds much better than a brand new one. And an older weapon is much more comfortable and broken in than a new one."

The other boys quieted down after that. Now, they were just waiting for Simon, who was the newest and only here for a week on a break from the Shadow Hunter Academy. Just before he had turned 18, him and Clary had become parabatai. After a year at the Academy, he was still not the best at drawing runes, and went very slow so he wouldn't mess up.

Jem looked over the group. Jace, who was so much like Will that he couldn't tell if the two Herondales would've been best friends or worse enemies; Alec, who was shy and timid unlike his ancestors, but looked so much like Will that it always came as a shock to him; Isabelle, who was so unlike Jessimine in every possible way; Clary, who's hair was as red as Henry's had been; Simon, who was, well, Simon. There really wasn't any other way to put it. Maybe he was similar to Sophie? No, not Sophie. Who did Simon remind him of?

He dropped the thought when they were finally ready to go. The night air was colder then London had been, and dryer. Not nearly as much rain, but the air still had that city-smell to it. The buildings were taller, younger, and it was much, much busier.

"So, you knew Magnus?" Alec asked to keep an awkward silence from starting.

"Yes. I knew almost all of your ancestors." He said, gesturing to the rest of the group.

"Were my ancestors as handsome as I was?" Jace asked, half joking.

"Depended on the day. But you can count on them being as stubborn and thickheaded."

"I'm not thickheaded!"

"Yes you are." Pretty much everyone said.

Jace just grumbled a little.

"You knew a Fairchild?" Clary asked.

"Henry Fairchild." Jem couldn't help but smile a little. "Invented the portal with help from Magnus. He was an interesting character, to say the least."

He never got to explain anymore, because just then, they were attacked.

" _You should be dead!"_

Jem froze when he heard that voice. He had been told the demon had been killed a long time ago. "Yanluo."

Someone bumped into him, and snapped him out of his trance. The disbelief was soon replaced with anger. This was the demon that made Jem an orphan, the reason he had been so dependent on that drug, the demon that eventually was the reason Jem had been unable to grow old with Will.

"You should be dead too." He growled, throwing a dagger at the Greater Demon. While it hit him, it didn't kill him. It just made him mad. The demon lunged, and Jem dodged, but then he realized Yanluo wasn't alone. Rogue werewolves were with him. The werewolves were keeping the other shadowhunters busy, while Yanluo was focused on Jem. The fight was a blur for pretty much everyone. While they had been out on a hunt, they had let themselves be distracted. A stupid mistake and they all should've known better. But Jace saw how the battle ended. At some point, Yanluo had lunged for Alec. Jace didn't have time to yell out a warning, but before the Great Demon could get to Alec, Jem had jumped in, stabbing the cane deep into Yanluo's head, but being smacked into a brick wall at the same time. It was hard to explain. The Greater Demons hissed as it died, ichor dripping down its face, around the dragon-headed cane.

The werewolves took off once they realized Yanluo was dead. Alec was the first one by Jem's side, having been the closest to the wall. The ex-silent brother was unconscious, bleeding badly from his head and from deep gashes in his side. Alec frantically felt for a pulse, and let out a breath he hadn't realized he'd been holding when he felt the faint thump of his heartbeat. Clary and Jace got on their knees next to him. Her stele already out, Clary quickly drew a rune on Jem's side and his head to slow the bleeding.

"Make a portal to the Institute." Jace told her, taking charge as he often did. "Alec, call Magnus. Isabelle, call Maryse and have her summon the silent brothers."

"What about me?" Simon asked.

"Help me carry him." Jace grabbed the top half of Jem, while Simon grabbed his legs. Clary already had a portal open, and they all stepped through, into the infirmary. The next few tense minutes went by in a blur, and the young shadowhunters waited in the hallway for updates.

 **Again, I'm sorry about how crappy and rushed that was. I just needed something to set the rest into motion. You'll see!**


	2. Way Back When

It was late that night when Magnus came out of the room, looking exhausted. No one had been told how Jem had been doing, and the Silent Brothers weren't letting anyone besides Magnus in or out of the room.

"How is he?" Alec asked, elbowing Jace who was beginning to doze off beside him. They were all tired, but didn't want to leave in case something happened.

"Alive." Magnus sighed. "Unconscious still, but they've stopped the bleeding."

"Then why won't let us in?" Jace asked, awake now.

"Because he won't wake up, and we can't figure out why." The warlock glanced towards the room, the look on his face saying he knew more than he was telling. Alec groaned and put his face in his hands.

"Why did he have to do that? I saw the demon coming, I was going to dodge." He groaned.

"You look like Will." Magnus stated. He didn't see the point in keeping them in the dark about this any longer. They deserved to know.

"Will Herondale? The one you wrote about?" Alec asked, tilting his head. "What does that have to do with anything?"

"William was James's parabatai." By now, the whole group was looking at him. They had all seen the faded rune on the ex-brother's shoulder, and they had all been curious about it. But no one had even been brave enough to ask. "James is still…" Magnus struggled for the words to best describe it. "He's still stuck in the past, in a way. I believe that he's come back to the modern world too quickly. Physically, he's healthy. But in his mind, he's mixing up the past with the present. He thought you were Will."

 _ **Jem's POV**_

He didn't remember much about the fight after he jumped at Yanluo. He hit the wall, and everything had gone black. And then there was a burst of colors, of the pinks of cherry blossoms and a bright blue sky and fluffy white clouds. He heard noises, but it took him a while to make them out. It was voices. He knew the voices, but it couldn't be right. When the source of the voices came into view, he sucked in his breath. There was his mother and his father and their friends and fellow clave members. He could tell from the clothes that they must've been just married. He watched from a distance as the party went on, in fast forward at the same time as slow motion.

As fast as the scene came, it left. Now there was a new one. It was his parents again, but now his mother was holding a little baby wrapped in blankets. It took only a second for Jem to realize that he was looking at himself as a baby. Born with a head full of black hair and as loud of a scream as infants can have. He never knew how much of a handful he was, until now, as he watched his life play before his eyes.

He would wake his parents up at every hour of the night, screaming bloody murder, until they brought his cradle into their room at night. Then he would only wake them up every two or three hours, wanting to be fed or held or changed.

As soon as he realized he could, he almost always refused to wear the cloth diapers they used back then. Before he could even walk, he would tug on the knots or the pins until they came loose. Then he would pull them off and try to throw them, giggling when someone found he managed to get out of it again.

He would scream and cry if anyone besides his parents held him. While anyone could sit in front of him and play with him, he refused to be held by anyone besides his mom or dad, and would scream and squirm until he was either put down or in the arms of his mother. Finding a babysitter than wouldn't quit proved to be quite a challenge.

When he could crawl, he would try to follow the other shadow hunters into the training room. The older girl, a teenager whose name he had long ago forgotten, was the only one who seemed amused by them and would chase him from the room, pretending to be some demon that was going to eat him. He would squeal in joy and crawl away as fast as he could.

By the time he learned how to walk, his father was at his wits end with baby James. He still refused to keep on the cloth diapers. Because of that, several rugs were ruined. No one wanted to baby sit him, because he was constantly on the move, breaking things, or would start to scream for no reason and make the whole Clave run out of the meeting, thinking something was wrong. It was like the boy who cried wolf.

There was a meeting one day, when Jem was probably close to four years old. He walked into the drawing room, and everyone in the room turned to him as he made his way over to his mother and crawled into her lap. He was supposed to be being watched by the older kids in the Institute. He muttered something quietly t his mother, but before she could answer, the head of the Clave snapped at them that a child shouldn't be in the room during a meeting. She had snapped back at him that he didn't understand and wasn't feeling good. The man had come over and grabbed Jem, aiming to give him to the group of teens who stood at the doorway. Jem had puked all over him. The older man had pushed him away in disgust, and Jem's father caught Jem before he would've hit the ground. All the yelling that followed scared the young boy, which made him cry, which only added to the noise. The meeting ended early, but his parents assured James that they weren't mad at him. They stayed up with him for the rest of the night while he got sick.

Then came the happier memories.

Not too long after James turned five, his father started to show him how to play the violin. Jem had gotten frustrated with it, but his father kept encouraging him to keep trying. When he finally got it, it was overjoyed. He felt like he could climb a million mountains in a day, because he had done it and made his father proud.

At night, Jem would lay in between his parents on a big rock in the yard, and look at the stars while cherry blossom petals floated down around them, landing in the small pond. He would fall asleep curled up against his mother, and then they would carry him inside and lay him on his bed.

He remembered when he got his first marks, at 7 years old. His parents had looked so proud when they saw it. He didn't flinch or whimper when he felt the burn of the stele. He had been too excited about them. Right after that, his father showed him a violin that he got him, so he would have his very own instead of having to use his fathers. Together, they would practice for hours. It was a rather peaceful time.

Then Jem was 10, and could start training more with weapons. But he was youngest, and by quite a bit. None of the others wanted to train with him. Jem had found this frustrating, and when one of the older boys teased him about being the baby of the house, Jem attacked him. Being caught by surprise, the other shadowhunter ended up with a broken nose before someone managed to pull an angry ten year old Jem off. Jem had stormed off, and wandered around in the gardens before he calmed down and decided that he wouldn't need anyone else to train with him. He could train by himself. So for the next few months, he would spy on the other young shadowhunters, and study the way they moved and how they fought, and then he would run out to the garden to try it himself with a little seraph blade he had stolen from the training room.

His mother had found him in the garden one day, and decided to help him train since no one else would and his father was busy. At first, as most young boys would, he didn't want to be taught to fight by his mother. But she explained to him that since he had her slender build, she would be the only one in the institute that could train him to use it to his advantage. Still a little reluctant, he decided to give it a try. Within a few weeks, it appeared as if they were dancing together, Jem moving more gracefully and using his build to his advantage. Finally, the others decided to let him train with them, where he showed that throwing knives was one of his best moves.

The next year, most of them left to experience other institutes or adventures. Soon, it was just Jem, his parents, one other shadowhunter, and the servants. That year was the year that Yanluo began to cause trouble in the area. The clave hunted for the Greater Demon, and rules were put down. His mother would no longer let Jem outside after dark. They no longer laid under the cherry tree on the rock to watch the stars, and there were no more violin lessons outside, or at all. He was on his own with the instrument now.

When he turned 12, his memories began to become fuzzy, harder to remember, and distorted. The demon Yanluo attacked the Institute, and after that, Jem can only remember excruciating pain and strange sounds and tastes. He couldn't tell if he was screaming, or if it was someone else. He couldn't tell what was real and what wasn't. Was it happening again?

 **Meanwhile in the Institute…**

Jem's body began to thrash around on the bed, and he was screaming out in a different language. The Silent brother's didn't know what was happening. At the sound of the screaming, Magnus had rushed back in, despite his exhaustion. For five minutes, they tried to calm him down and find out what was wrong. But after those five minutes, he quieted down as if nothing had happened. Magnus sighed.

 _D*mmit James…don't make me have to explain that you died to Tessa…_


	3. When He Met Will

**Please review. I'm lonely. Comment something. Anything. Suggestions. Faces. Quotes from the books. Anything!**

 **Day 2 in coma…**

It was the second day since they had gone demon hunting and Jem had been knocked out. The ex-Brother still had yet to wake up. No one had been able to get ahold of Tessa either. The young shadow hunters were sitting in the library, waiting for any news. Last they heard, nothing had changed. But that was right after dinner the night before, which no one had really been too interested in. It had been more of a "there's food in front of me so I'm gonna eat it" dinner.

Alec was sitting on the couch, staring at the table, lost in thought. Jace was stretched out over the couch, his head on Alec's lap, sleeping. Clary and Isabelle were sitting in chairs, and Simon was laying on the floor between them, absentmindedly throwing a tennis ball in the air and catching it. The girls were both looking for some way to find out what was wrong with Jem.

Finally, Magnus came in the room. Before he said anything, his eyes wandered to Jace and Alec, and he pointed with an eye brow raised. Alec looked up.

"Food poisoning from the Chinese last night." He explained. "He was up all night puking his guts out."

"Ah." Magnus nodded. Everyone else looked up, expecting an update. "Anyway, there's been no change since last night. James is still unresponsive. We've tried everything at this point."

"Aroma therapy?" Isabelle asked.

"Yep. Nothing." Magnus shook his head.

"What if I tried to make a rune to wake him up?" Clary suggested.

"That might do more damage."

"But you have a theory." Alec said it as a statement, not a question. He had started running his fingers through Jace's hair, just as something to keep his hands busy.

"I do have a theory, but I'm not even sure it's possible." Magnus sighed.

"Explain?" Alec coaxed.

"I think he might be watching his life flash before his eyes. I'm not going to explain more than that, because I don't think he'd want me to. But if you're really curious, look up the Shanghai Institute in the 1800s. 1860s would be the most useful to you, and every year after that. Then try the London Institute in the 1870s." Magnus explained. "That way, whatever you find out is from a book and not me."

 **Jem's POV**

Much of what happened next was a blur, a mix of strange sounds and voices and excruciating pain. He could hear his mother's voice and his father's voice calling out for him. Then it seemed like there was just his mother's voice, and eventually no voices at all but the rough, unpleasant voices of demons taunting him from behind the darkness. Hallucinations mixed with reality. By the time he could make sense of things again, he was lying in a soft bed, a warm blanket over him and comfortable pillows under his head. Where was he? He looked around. He was in a plain room and it wasn't in Shanghai. That was all he could tell. He pushed himself into a sitting position, and looked around, confused. Where were his parents? How did he get here? Where even _was_ here?

Just before he could push himself to his feet, a woman walked in, marks dancing over arms and neck. So he was with other Shadow Hunters. That was good, right?

"Don't try to get up. You need to rest a little longer." She said, in a very soothing voice.

"Where am I? What happened?" it hurt to talk, and his voice was hoarse, as if he hadn't used it in a while. The slight Mandarin accent seeped through, barely noticeable.

"You're in the hospital, in Idris. You're safe." She said, sitting on the edge of his bed and carefully pushing him back down so he was laying down. "Do you remember anything?"

James shook his head. "Where's my mom?" He asked. "And my dad?"

When he saw the frown on her face, he felt a wave of dread go over him.

"We didn't get there in time to save them. You were the only one still alive, and just barely." She said sadly. She explained how the enclave had found him and his parents tied to chair, and how both his parents had already been dead. He had nearly been dead, his eyes white and blood at the corners of his mouth and splatted on his pants and shirt. She told him that he would be given the choice to stay in Idris, or go to another institute, but it was not suggested he return to China any time soon. When he asked if there was any other family he could go to, he was told the remaining Carstairs had gone off to hunt Yanluo for revenge. He asked for more time to think about it.

The next few days were spent in physical and mental therapy. They explained to him about the drug, yin fen, and how he would die slowly if he took, but die within a day if he stopped taking, and either way it would probably be painful and harsh. He had thought about it, and decided to keep taking the drug so he could have the chance to hear them say Yanluo was dead, and in the hope they would eventually find a cure for it. He had to regain some stamina, as it had become a struggle to even walk down the hallway. He couldn't hold heavy objects. Mentally, he was haunted by screams and voices, and would have panic attacks. The smallest things seemed to trigger some memory of whatever had happened in the Shanghai institute, and he would start to shake and his breath would come in gasps as he re-lived the torture he had gone through. He was afraid of the dark now, too, as if he expected Yanluo to jump out at him from any shadow.

When they finally deemed him fit enough, they asked him where he wanted to go. An institute or stay in the city? He told them the London Institute. His father was from London. He had no idea how big of an impact the London Institute would later make on him.

They sent him off with the silent brothers, making sure he had enough yin fen to get through a few days and had sent a letter ahead of him to Charlotte Barnwell to tell her about the condition of her newest shadow hunter.

The ride to London took a few hours, and Jem was not liking traveling by carriage very much. He used to walk to places in Shanghai. Now, he honestly felt a little nauseous. He couldn't see from the windows, because they had the curtains closed and they told him to keep them that way. The rocking of the carriage and occasional bump left him nauseous and dizzy. He swayed a little as he stepped out, and was briefly self-conscious of how he must look; an underweight, pale skilled, half Chinese boy with hair that was streaked with silver.

Standing at the door to the massive Church building was a small woman, with messy hair and kind eyes. Jem took a step toward her, and heard the carriage pull away behind him. He would be staying here in London for a while now. He had been quickly told before he left that there was another shadow hunter boy around his age here who he might be able to befriend. After a tour of the massive institute by the woman, whose name he learned was Charlotte, he was brought to the training room to meet the other shadowhunter. His name was William Herondale, and he was apparently very hard to get along with, according to Charlotte.

 **(. I can't find the part of when Will and Jem first meet online anywhere! I packed my books away because I'm in the process of moving, but why didn't I make a note of that part beforehand!? Ugh, you all know how it went, so *insert Cassandra Clares words of what happened when Jem and Will first met and Will agreed to train with Jem*)**

Jem stayed in the weapons room with Will for a while longer, already trying to show him how to properly throw a knife. So far, there was very little change. Will was horrible at it, and not very patient with his failing. There were now several more holes in the walls and Jem had decided the safest place to stand was behind Will on his non-throwing arm side.

"Maybe you should just take a break for a while. I don't think a broken window will do anyone any good." Jem said carefully, seeing Will red-faced and dripping with sweat as he glared at the target. If looks could set things on fire, that target would've been a pile of ashes by now.

"No. One more try." Will argued, pulling his arm back like he was going to throw a football.

Jem sighed. "You said that four tries ago." He walked over to Will's other side and grabbed his wrist before he could throw it again. "And if you're going to try one last time, then try to do it right. It doesn't matter how strong your arm is, if you can't throw it right, you're not going to get anywhere. First off, it's all the wrist, not the shoulder."

Jem guided Will's arm lower, so it was by his side again instead of behind him. "Second, you should be standing sideways, like I said _twelve times_ already." He put his hands on Will's shoulder and moved him so he was standing sideways to the target, instead of facing it. "Now pull your arm in front of you and.." Jem tossed a knife with a quick jerk of his wrist, much like how someone would throw a Frisbee today. The knife hit the target in the dead center, as it normally did.

"Try it now." He instructed. Will bit his lip in concentration and eyed the target, before copying Jem's earlier movement. The knife cut through the air and landed in the circle around the bull's-eye. The closest he had gotten so far. Will grinned.

"Much better." Jem nodded. "Maybe there's hope for you after all."

"How did you learn to hit the center every time?" Will asked him, turning those startlingly blue eyes towards Jem.

"I can't hit it every time. I just hit it most of the time." Jem corrected. "My mother taught me."

"A girl taught you how to throw a knife?" Will rose an eye brow.

"Is there a problem with that?" Jem copied his facial expression.

"No, none at all." Will turned his gaze away, looking a little smug still. "I'm hungry. Did Charlotte show you the kitchen?"

"Yes, she did." Jem nodded.

"Well, I'm sure it'll be more interesting when I'm there. Come on, I'll show you how to sneak in and steal fruit."

"Why steal? Couldn't you just ask for it?" Jem asked, tilting his head a little as he hurried to catch up to Will, who was already walking away.

"I could, but where's the adventure in that?" Will snorted and lead the way, Jem following closely behind him.


	4. Drug Deal

By the time Magnus had managed to get a hold of Tessa, Jem had been unresponsive for about a week. After the strange day when he seemed to be panicking and was trashing around, he hadn't moved besides the gentle breathing. He would lay still for hours, seeming to completely at peace. Tessa wasted no time in getting there, going though a portal and following Magnus into the room.

"What happened?" She asked as she sat on the bed next to him, reaching up to brush the hair off his forehead. He didn't have a fever, and the Silent Brothers had claimed he was perfectly healthy. They weren't sure what was wrong.

"Yanlou came back." Magnus sighed. "He attacked Jem and the others while they were hunting, and when he went towards Alec, Jem jumped in, killed the demon –for now- but was slammed against the wall. I think he thought Alec was Will."

Tessa sighed, and ran her hand along Jem's jaw line. He didn't move or show any sign that he felt it. "So whats wrong with him? There's no fever, there's no swelling…he looks like he's sleeping." She looked up at Magnus helplessly. "I just got him back, after so many days without him. I can't lose him yet, Magnus. It won't be fair for him to lose his life so early again."

Magnus rubbed the back of his neck. "I'm not sure whats wrong. I think that maybe he's reliving his past. The way he was thrashing that second night, I think it was, he was calling out in Mandarin. Then he got very still and quiet, and hasn't really moved since. Every now and then I would notice a finger twitch or a slightly deeper breath, but he hasn't made another sound."

 _ **Jem's POV**_

Jem had been in the institute for a while now, almost two weeks. He felt stronger than he had in a while, and he had grown close to Will. He seemed to be the only one in the whole institute who could get along with the black-haired boy and stand him for more than a hour at a time. He had been pretty good about hiding the drug from the other children too. Will and Jessamine, who wasn't very friendly at all, both only knew that he was sick and needed a special medicine everyday. They didn't know that it was a warlock powder that he would be considered an addict by many people.

Tonight he had to go get more again. Once a week, he would go get new yen fin, hoping to get only a weeks supply so no one would find it in his room. Will would often just invite himself in after Jem had woken him up several times in the night with his nightmares. The nightmares would leave him screaming and unable to wake up. The first time he had one and Will had woken him up, he had panicked and punched Will in the face, throwing the other boy to the floor. Will hadn't been mad, more shocked than anything, and he had since then came in Jem's room whenever he wanted, pretty much, to make sure Jem was okay. And he never asked for the story of what the nightmares were about, which Jem appreciated.

If he had a small enough stock of the drug, he could easily hide it between the mattresses or under the bed. He waited until it was dark and he was sure everyone was in for the night before he climbed out of bed and pulled on his gear. He drew a few runes on himself so the mundanes wouldn't notice him, and then slipped out of his room and down the hallway. He made his way down the many stairs and out the front door, through the gate and onto the streets. He didn't see the shadow watching him from the window.

As Jem made his way down the streets of London, he kept thinking about how different this place was from China. The people were very different, all looking like his father and much taller than he was used to. The clothes they were even seemed different, and the food was very different. It was still good food, but he missed the food in China. London was very wet and damp, and that wasn't very good for his already bad joints. If he went long enough without the drug, his joins would ache and he felt like an old man. The dampness in the air only made that worse.

He found the first den he could, where the stench of demons was strong. This was the same one he had come to last week. He hesitated at the door for a split second, before going in. It was loud and the floor was sticky under his boots. Was it blood or spilled drinks? He wasn't sure he wanted to know. Squeezing his way past the many drunken demons, warlocks, fey, and the few foolish mundanes, he got up to the counter and passed the warlock who ran the den a slip of paper with some money. It was a quiet exchange, as this warlock was understood Jem's problem. His best friend had died from the drug.

Jem hurried back outside, relieved to get out of there without a problem. Despite the dens being supposed "safe places" for nephilim and downworlders, he still felt nervous being around so many by himself. He knew they watched him. With a sigh of relief, he turned away from the building and paused, eyes wide, as he saw the questioning glare of his only friend's blue eyes.

"What are you doing?" Will asked, his voice even and unreadable.

Jem could see no way to avoid this. If he tried, he would make himself look like a hopeless addict who was killing himself on purpose. "I'm getting my medicine."

"Here? This doesn't look like a pharmacy to me." Will crossed his arms. "Come to think of it, I don't recall ever hearing about a medicine that turns people's hair and eyes silver."

Jem knew that Will had him cornered now. There was no beating around the bush with it. So he explained everything. Everything from the demon attack at the Shanghai institute, waking up in a hospital and being told that his family and everyone else he had grown up with there were dead, and the experiments to get him off the drug.

"If I don't take it, I'll die within a day, and very painfully. Taking it will lengthen my life, if only by a little while. I'm not ready to die yet." He finished, looking down. "I hate everything about it. I hate buying it, I hate taking it, and I hate what it does to me. But I have to take it."

The two boys stood there in the street for a few seconds, quiet. "If you want, I could go buy it for you." Will offered.

Jem was about to protest, shocked that Will would offer to do it.

"I don't mind, really. I saw they way everyone was looking at you. It was like they were sizing you up. You don't fit in with those kind of people. You're too nice. I can fit in better, and they wont try anything with me." Will insisted. "Your nightmares aren't just nightmares, are they. They're flashbacks."

Jem sighed, and nodded. "Very vivid flashbacks. Sometimes though, I see myself coming into one of these dens, and there's Yan Lou again, waiting behind the counter to poison me more."

"So let me buy the it for you." Will said. "You'll feel better when you don't have to go in them any more."

Jem nodded, giving in. He was relieved at the thought of never going back in there, but he wouldn't admit it. "I'll give you the money for it. It's not very cheap."

Will nodded. "Come on, lets go back. It looks like it's going to down pour on us any minute."

A few minutes later, the boys were rushing inside, soaking wet.

"I don't think I like London very much." Jem grumbled, wiping the water off his face.

"You aren't leaving though, are you?" Will asked. "It's an awfully dull place around here with no one else to blame for the missing fruits in the kitchen."

"They don't blame me. They know it was you."

"Yes, but it's the thought that counts."

Jem shook his head, amused. "I suppose I can stay for your entertainment."

"Good, because Jessamine isn't very entertaining at all."

Jem rolled his eyes as Will shook his head like a dog, and followed him upstairs, branching off to his own room while Will went down the hall to his own. It felt good to have told someone else about what had happened. He hadn't told Charlotte or Henry exactly what had happened, but he had a feeling the Silent Brothers had filled them in. Now that he had confided in Will, he felt better. Maybe London wasn't so bad after all.


	5. Eyes Like The Moon

**Thanks for the reviews! Continue to do so, so I have the motivation to continue writing!**

Tessa and Magnus stayed up for most of the night with him, trying desperately to figure out what was wrong with Jem. But there was nothing they could find. Even when Tessa tried to turn into him, for once she got no insight to what was happening inside his head. There was no thoughts she could find, no sign of what was happening. She turned back to her own body.

"Nothing. I can't find anything. It's like he's just asleep." She sighed, rubbing her temples as she sat on the edge of his bed. Magnus frowned and rubbed her back. She had brought Church with her when she came, and now the cat was curled up on Jem's chest. Unlike the rest of them, the cat seemed completely relaxed, purring quietly as he snuggling against his human.

 **Jem's POV…**

Jem and Will, dressed in their black gear, stood back to back as they fought a few low-level demons. They were tracking demons, nothing worth memorizing. Henry and Charlotte were with them, but had run off after another demon, leaving the boys to fight off three on their own. After training together for the past three weeks, the two knew each others moves as easily as their own. They had grown very close.

Jem slashed with the seraph blade as he dodged under a leaping demon, and Will stabbed upwards, slashing open it's stomach and dodging the splattering ichor. Jem stepped to the left, and Will went to the right and they both stabbed between them, blades digging deep into the second demon. The third one was more of a challenge as it turned and tried to run. The boys took off after it, too caught up in the excitement of the hunt for Jem to register the growing ache in his joints.

Will was soon ahead of Jem, and he was ontop of the demon before Jem was able to catch it. Jem's chest burned and he doubled over, catching himself on a tree as coughs exploded through him, burning his chest and throat. Will didn't seem to notice. The black haired boy was busy trying to kill the demon, and he did exactly that ease, once he stopped toying with it. Just as William was about to brag to Jem about his kill, he noticed his silver-haired friend struggling in his coughing fit. Blood splattered his sleeve and speckled his lips.

"James?" He asked, eyes wide. "What's wrong?"

"My…medicine." Jem slid down to the ground, the ache in his legs too much for him to stay standing.

"What can I do?" Will asked, going over to him. "Would an izrate work?"

Jem shook his head, wiping his mouth. "I need my medicine." He wheezed. Will wasn't sure what to do. Jem's medicine was all the way at the institute, and he had never seen anything like this. Sure, there had been a day or two when he would claim to not feel well and be a little paler and stay in bed for most of the day, but never had he seen Jem cough up blood.

Looking around, he spotted Henry's bright orange hair and Charlotte's small frame next to him. He called out to them and the two older shadowhunters turned and hurried over.

"What happened?" Charlotte demanded.

"He needs his medicine." Will explained.

"Can you walk?" She asked Jem, bending down to eye level. Jem's eyes were in and out of focus, almost completely silver now. Will had watched during the last few weeks as Jem's hair and eyes slowly became more and more silver. Yesterday he noticed that more than 3/4s of Jem's eyes were silver, now looking speckled with a few small specks of brown. His hair still had some dark streaks, but it was mostly silver as well. It was chilling, like looking at a ghost.

It took Jem a minute or two before he seemed to understand what Charlotte was asking him to do, and he tried to push himself to his feet. His arms and legs shook with the effort, and when he tried to take a step, his legs gave out under him. Will caught him before he fell. Henry came ove rand picked Jem up as if he weighed as much as a spoon, and they hurried towards the road where the carriage waited. Jem's head was resting against Henry's chest, coughs racking his body more and more frequently.

When they got to the carriage, he handed Jem to Charlotte and jumped into the drivers seat in the front. With Charlotte, Jem, and Will in the back, he whipped the horses onward and they raced back to the institute. In the carriage, Charlotte was trying to keep Jem awake, telling him to focus on her. But he had begun to lose touch with reality it seemed, eye unfocused and filled with fear. He would mumble in a different language that Will didn't know, and that scared him.

Pulling into the institute, Henry hurried to get Jem up to his room while Charlotte rushed off to summon the Silent Brothers. Will followed Henry, being the only one who knew where Jem kept his Yin Fen. He opened the box with the woman on it –he couldn't remember her name or what she did- and took a pinch of the silver powder and tried to give it Jem, but his silver-haired friend screamed a blood-curdling scream, yelling something in another language –Mandarin most likely-, and started thrashing on the bed. He smacked the powder out of Will's hands before Henry managed to restrain his arms, and Will grabbing his legs, holding them down. Jem's eyes were pale now, like the moon.

It seemed like forever before the Silent Brothers came in and Will and Henry were forced out of the room. Will paced outside the door, shocked by his own worry. Yes, he had allowed himself to befriend Jem since he was dying anyway, but was his curse making Jem this sick? He didn't realized he had grown so attached to his half-Chinese friend.

"Will, do stop pacing. He'll be okay." Charlotte insisted, watching him.

"I'll stop when he can say that, not you." He retorted. Again, it seemed like hours passed before the silent brothers came back out.

 _He is exhausted, but he will be okay._ Their voices said in the shadow hunter's heads.

Will pushed past them and into the room, having to see it for himself. Sure enough, Jem was still laying in the bed, no longer thrashing. His hair seemed a little more silver, and he was fast asleep, but Will could see the gentle rise and fall of his chest as he breathed. Will sat in the chair beside the bed, and sighed in relief. It looked like Jem had a fever, with his silvery hair clinging to his forehead, but he was alive.

"Will-"

"I'm staying here." Will crossed his arms and glared at Charlotte and Henry as they poked their heads in. The two adults sighed, but there was nothing they could do. Talking sense into Will when he was in a mood like this was impossible. So instead Charlotte went to ripe his forehead with a cold cloth that the brothers had left on the nightstand. Sighing, she put the cloth back in the bowl before looking at Will. "If _anything_ changes, William, come get me or Henry." She told him firmly.

"Yeah, yeah, go do you head-of-the-institute stuff." He waved at him impatiently, and with a slightly annoyed sound, she turned and lead Henry out of the room.

Will sat there for a good three hours before Jem stirred, his eyes fluttering open and looking around in confusion before he realized where he was.

"How are you feeling?" He asked when Jem's silver eyes landed on him.

"Tired. But I'm okay." Jem yawned and pushed himself slowly into a sitting position. His arms shook a little as he did so.

"Do you need more of the medicine?" Will made to get up, but sat back down when Jem shook his head.

"I've had enough of it for tonight. I guess I just need to take more before we go hunting."

For a few minutes, Will was quiet. Then, "Jem, will you be my parabatai?"

Jem looked taken aback. "Me? Will, don't waste that on me. A parabatai should be able to be there with you for a lifetime, but I only have two or three years at most. Find someone who can be there for you."

"I don't want anyone else." Will insisted. "Maybe we can find a cure, and then you'll be there for a lifetime. You're the only one who can put up with me, James, and you're the only one I trust at my back."

"William-"

"How about if I can disarm you once you get back on your feet, you be my parabatai. If I can't disarm you, then I won't ask you again." Will looked desperate, as if this was the most important thing in whole life to him. How could Jem deny him that chance? Will wasn't very patient and surely Jem could disarm him. They had been a pretty even match so far, yet with Jem's smaller frame, he tended to win a little more often than Will. He was fully confident that he would win, and Will would be able to find another shadow hunter to be his parabatai, one that would last him longer.

 **Kind of short, but it never did say in the books when, where, or what caused Will to ask Jem to be his parabatai. So I figured this would make some sense.**


	6. Parabatai

**So, so, so, so sorry it took so long to update this! Writers block, plus school, plus I working on The Gender Game (A Criminal Minds fanfiction that is now complete), and reading the Harry Potter books for the 1** **st** **time. I'm a bit behind on a few fandoms, lol. Anyway, I have a new Harry Potter Fanfiction up, called If Fred Lived, which clearly is a story about if Fred hadn't died in the last book. Of course, I try to make as believable as possible, so he does get seriously injured. But hey, injury is better than death in most cases.**

 **Anyway, here's the next chapter. It's going to be a little short, because the Codex doesn't have a lot on how the parabatai ceremony thing works.**

 **Jem's POV**

In the very back of Jem's mind, he could hear Tessa and Magnus talk, he could hear the voices of the younger shadowhunters, and he heard the voices of the Silent Brothers. He did not know what they were saying, but he knew they sounded worried. He wanted desperately to assure them that he was okay. Or at least, he wasn't in pain. But no matter how hard he tried, he couldn't make himself move or speak. Instead, he continued to watch his life flash before his eyes, watch memories of a life so long ago, memories he had nearly forgotten.

Now he was watching that fateful day when he became forever bonded with Will, the most difficult and most loyal person Jem had ever known. The anti-social boy who became his closest friend, his brother in all but blood. Standing across from each other in the training room, the boys began to circle. Jem's silvering hair sparkling where the light hit it. He had taken enough of the drug to get him through the day, hopefully. Now he just had to make sure he would win so Will would have a chance to get a better parabatai, someone who would have a lifetime to give to him.

Will lunged first, darting to the left before changing direction at the last second and going right. Jem spun out of the way, throwing a star at Will's feet to try to throw the other boy off balance. But Will seemed to be expecting it, and easily dodged, not wasting a second in going back after Jem. Their seraph blades flashed as the boys danced around each other. They moved already as if they were one, anticipating each other's next move. They had been training together almost every day since Jem got here, taking a break only when Jem's health required it. And on the days when Jem was stuck in bed, they would sit together and go over different types of weapons and demons and how to kill the demon, what weapons worked on certain downworlders, and sometimes looking for a cure for Jem's addiction. In a way, they didn't need the parabatai rune to be bonded. They had taken to each other like a fish to water, relying on each other for everything.

Jem spun around and threw a small dagger towards Will's hand. Will smacked it aside with his own blade and jumped forward gracefully, knocking into Jem, who already had a blade out and ready, and forced him off balance. Jem hadn't expected Will to run _towards_ him while he was holding a weapon out in front of him. But it seemed Will had thought this through a bit more than Jem had expected, because the next thing he knew, his seraph blade was clattering to the floor and Will stood over him, looking victorious. Jem could only blink at him.

"Shall we go tell Charlotte to get the Silent Brothers then?" Will asked, grinning.

Jem wasn't sure what to say at first. "Are you sure you want me to be your parabatai? I'm _dying_ William. I won't be around very long-"

"Stop it. I know you're not guaranteed to be there with me forever, James, but it's okay. I want you to be my parabatai. Not anyone else. And if you go before I do, than I only ask you wait for me on the other side so we can continue to be parabatai in the afterlife, whatever does happen after death." Will interrupted. How could Jem argue with him? Will had a way with words, and if he was going to be honest, he felt the same. He wanted to have a parabatai ever he was little, and he wanted his parabatai to be Will. He only hoped they found him a cure before it was too late.

"Let's go tell Charlotte then." Jem said, and held out a hand for Will to help him up. The blue-eyed boy smiled, a real smile, and pulled Jem back up to his feet.

Charlotte had taken the news better than Jem had expected. In all honesty, he had expected she would have the same reaction he had: wishing Will would chose someone who would be there longer. OR maybe she did think that, but didn't want to hurt Jem's feelings. Either way, she seemed very happy for them. Happy that for once, Will seemed to have opened up to someone and trusted them. Happy that Jem would have a friend for the time he had left. She wasted no time in calling the silent brothers for the ceremony. It would be done at the Institute, with just the silent brothers, Charlotte and Henry, and the maids/servants. They would be coming the very next day.

So for the rest of that day, Jem and Will wandered the streets of London, not really looking for demons to hunt, but being alert for any anyway. Will showed Jem the different spots in London he liked best, the different things he had learned about the places through the books he had read and the demons and downworlders he had often found near each place. When Jem began to tire, they headed back to the Institute, where they had dinner and went to bed shortly after. Tomorrow would be the day that would change their lives forever, the day that would cause them so much joy and pain and neither one would have traded it for anything.

Jem had another sleepless night, haunted by nightmares and flashbacks of the attack on Shang Hai. He found himself pacing his room before taking more of the drug, dropping the pinch on his tongue, too impatient to let it dissolve in water. Then he pulled out his violin, something he hadn't played since he had woken up in the hospital. He ran his fingers over the soft, polished wood. The strings were still new looking. He plucked at a few string, and soon found himself tuning it before putting it to his chin, taking up his bow, and dragging it along the string. Soon the halls filled with the sound of Jem's music, and he found himself expressing his nightmares, his sadness, and his loss in the notes he was playing. Then he changed it, instead expressing his first impression of the London institute, shocked and a bit shy at first. He played about when he first met Will and the things Will had said to him, and he played Will agreeing to train with him. He played about when Will found about the drug and told Jem he would help him get it, played about the episode he had on a demon hunt, and played about their spar in the training room, the one that meant they were now to be parabatai.

Morning came slowly, and Will came in to wake him up as he often did, even though Jem was rarely ever still sleeping. They made their way down to the dining room, Charlotte and Henry already sitting down and eating their breakfast. Neither Jem nor Will ate much that morning. There was far too much excitement for that. In the time they had to wait, they were in the training room, practicing their throwing of knives. Or at least, Will was practicing while Jem showed him how to do it.

Finally, the time came. Brother Ecnoch came, as well as two other Silent Brothers the two hadn't seen before. Runes were drawn on the floor and three circles of fire erupted onto the floor. Two not touching, and the third connecting them. Will and Jem stood in the center.

 _William Herondale, do you accent James Carstairs as your parabatai?_ Said the voice of one of the brothers.

"Yes, I accept him."

 _James Carstairs, do you accept William Herondale as you parabatai?_ The Brother asked.

"Yes." Jem nodded.

 _As you draw the rune on the other's arm, say the oath of the parabatai. Wither thou goest, I will go; Where thou diest, I will die, and there I will be buried; The Angel do so to me, and more also, If aught but death part thee and me."_

Will went first, drawing the rune on the side of Jem's throat, saying the oath.

"Wither thou goest, I will go; Where thou diest, I will die and there I will be buried; The Angel do so to me, and more also, if aught but death part thee and me."

This rune hurt a little more, much like how it felt to get his first rune when he was so much younger. But Jem didn't flinch. He could feel the power of the rune, the ache as if it was reaching out for it's partner. He took his stele and drew the parabatai rune on Will's chest.

"Wither thou goest, I will go; Where thou diest, I will die and there I will be buried; The Angel do so to me, and more also, if aught but death part thee and me."

Will didn't flinch for the rune either. The fire around them soared upward, but there was no heat from them. Jem could feel the power of the rune on his throat. He felt suddenly stronger, as if he could go twice as long without the drug, fight twice as many monsters. It was done. Jem now had a parabatai, a brother who was closer than a twin would be. Somehow, that thought made Jem feel as if London was warmer, as if the air smelled nicer, the world was cleaner and more peaceful and he could finally live the rest of his years in the pleasant, ironic peace a shadow hunter found in hunting demons and protecting mundanes. This rune made Jem feel as if he had a chance at a longer life, a less painful ending.

 **Sorry it's so short, I couldn't find anything on the actual details of the ceremony. And according to the wiki page, I went out of order. It wasn't until a year after Jem came to the institute that Will asked him to his parabatai, and a year after that when the ceremony actually happened. But I would think that since they all thought Jem would live only 2-3 more years, that they would rush it a little.**

 **And again, I'm sorry it took so long to update! I'll try to update a bit more often, I'm going to try to work out certain days to work on certain fanfictions.**


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